A bacon sandwich (also known in parts of the United Kingdom and New Zealand as a bacon butty, bacon bap or bacon sarnie, in Ireland as a rasher sandwich[1] and as a bacon sanger in Australia) is a sandwich of cooked bacon between bread that is usually spread with butter, and may be seasoned with ketchup or brown sauce. It is generally served hot. In some establishments the sandwich will be made from bread toasted on only one side, while other establishments serve it on the same roll as is used for hamburgers.

Bacon sandwiches are an all-day favourite throughout the United Kingdom.[2] Its prominence in British culture is such that in a UK poll it was ranked the number one thing people love about Britain.[3] They are often served in British cafes, and are anecdotally recommended as a hangover cure.[4]

The BLT is a popular variant of the bacon sandwich with the additional ingredients of lettuce and tomato, but served cold.[5]